First of all i wouldnt ask the question "So howmany point do you have then ?" not becouse its a too-strong neg , but becouse it quite easely for her to dominate the frame. (first answer that came to mind was: " dont worry,i got so many points i aint even in your leage" or any answer along that line)
I would say negging her is a must , but dont try lead conversations to 1 specific routine, unless u have really strong frame control (a conversational master). Try to adapt your routines to the conversations.
The Question u gotta ask yourself is , am i willing to "steal" this girl from her current relationship, and am i willing to risk the "friend-like" relationship we have now for the chance of something more ? (karma is a biatch)
When she starts about her Bf , dont question or ridicule that relationship, let her do it. Try commenting " ... and here u are talking to me" and just see how she reacts (some find this line to dangerous to use , but i give this example as it illustrates the idea, and becouse it has givn me some verry nice results in the past , but again karma is a biatch

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If u are looking for something more hardcore there are some post about Bf-destroyer routines on this forum, do a search.
keruli